Above: Brown marmorated stink bug. Photo credit: John Obermeyer.
Most homeowners in northern Indiana are now quite familiar with the brown marmorated stink bug (BMSB), Halyomorpha halys. After enduring the great invasions of ladybugs (Asian lady beetles) in the late 1990s and early 2000s, this insect may be the one most homeowners would now crown as most annoying. And, it stinks!
The stink bug is aptly named for its stench and marbled, streaky appearance. It releases a pungent chemical as a defense mechanism when threatened. It is a potentially serious pest for homeowners and fruit growers in particular, but can also affect certain vegetables and field crops. Unlike the Asian lady beetle, which has some redeeming qualities as a predator outside, this relatively new insect is a pest both inside and outside.
Brown marmorated stink bug with identification clues included. Photo credit: John Obermeyer.
Indiana is home to other common stink bugs: the predatory stink bug (Podisus maculiventris, also brown in color and beneficial), the one-spotted stink bug (Euschistus variolarius, brown in color, a pest of crops) and the green stink bug (Acrosternum hilare (Say), a pest of landscape plants and soybeans), and others. The predatory stink bug and one-spotted stink bug are somewhat similar in appearance to the brown marmorated stink bug (BMSB), but lack two light bands on the last two segments of their antennae.
BMSB is a native of Japan, Korea, China, and Taiwan, and was first reported in the United States in Pennsylvania in 1998. The invasive pest has also been found in other eastern and midwestern states; it was first confirmed in Indiana in 2010.
The insect can invade houses in the fall, much like the multicolored Asian lady beetle. The bugs will not cause damage in the home, but will be annoying and will smell bad when disturbed.
Experiences in other parts of the country indicate that the brown marmorated stink bug first will be a pest in homes for a few years before it becomes a crop pest. As with the Asian lady beetle, homeowners should take steps that include caulking around windows and repairing screens to prevent invasion. Exterior surface applications of insecticides may offer some protection.
Once inside, homeowners can use a broom and dustpan, or a vacuum equipped with a vacuum bag. After collection, bugs can be drowned in soapy water. If using a vacuum, be sure to destroy the vacuum bag after collecting bugs. Stink bugs left inside a vacuum cleaner may begin to give off a disagreeable odor.
The heaviest damage in orchards tends to be in rows bordering woodlands in the tops of fruit trees. In apples, the insect can cause “corky” spots under the skin that can become somewhat sunken or “catfaced” over time. Damage can occur on peaches, apples, nectarines, and pears.
In vegetables, researchers said peppers, tomatoes, sweet corn, okra, and beans suffer the most damage. They reported that BMSB can transmit yeasts and bacteria that can damage fruit and cause rots.
Vegetable growers in the mid-Atlantic region have achieved some success in managing this crop with floating row covers – a physical barrier that prevents the bug from getting to the crop during periods of peak activity. They continue to experiment with trap crops, pheromone monitoring traps, and biological controls.
For additional information, consult Purdue Extension’s most recent publication on this pest entitled, “Brown Marmorated Stink Bug in Homes” at www.edustore.purdue.edu. Additionally, a lot of in-depth information about BMSB, including what researchers are doing about BMSB in specialty crops, is available at: http://www.stopbmsb.org/.